JP2848877B2 - Method for producing acid-containing polyolefin wax - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an acid group-containing polyolefin wax, and more particularly, to a method for producing a polyolefin wax by contacting the polyolefin wax with oxygen or an oxygen-containing gas in a molten state with stirring. The present invention relates to a method for producing an acid group-containing polyolefin wax capable of increasing an acid group addition rate by suppressing viscosity increase of a polyolefin wax in a molten state and improving stirring efficiency when providing an acid group.

TECHNICAL BACKGROUND OF THE INVENTION Polyolefin waxes are widely used in various applications such as fiber finishes, floor polish, paper treatment agents, water-based inks and water-based paints. Many of the usage forms of the polyolefin wax used for the above applications are water dispersions, and the water dispersions are produced by adding acid groups to the polyolefin wax. Conventionally,
One method of adding an acid group to the polyolefin wax is to oxidize the raw polyolefin wax by contacting it with oxygen or an oxygen-containing gas in a molten state with stirring.

For example, Japanese Patent Publication No. 48-37991 discloses a halogen compound of titanium and / or vanadium supported on the surface of a carrier comprising fine particles of an inorganic compound insoluble in magnesium or a hydrocarbon containing magnesium and aluminum, and an organic aluminum compound. Of polyethylene wax having a molecular weight of 500 to 20,000 obtained by polymerizing ethylene at 120 to 250 ° C in the presence of hydrogen and / or an olefin having 3 or more carbon atoms in an inert hydrocarbon solvent, using as a catalyst. After that, a method for producing a polyethylene oxide wax is disclosed in which the material is kept in a molten state at 120 to 200 ° C. and oxygen or an oxygen-containing gas is supplied therein.

Also, JP-A-50-119889 discloses a viscosity average molecular weight.
By contacting an ethylene polymer of 500 to 20,000 with oxygen or an oxygen-containing gas in a temperature range of 150 to 185 ° C., the ratio of melt viscosity / intrinsic viscosity of the ethylene polymer is 1,800.
A method for oxidizing an ethylene polymer, which is characterized in that an oxidation treatment is performed so as to be up to 10,000.

However, in the method for producing an acid group-containing polyolefin wax by a melting method, when an oxygen or oxygen gas is brought into contact with a relatively high molecular weight polyolefin wax in a molten state with stirring to give an acid group to the polyolefin wax, an oxidation reaction occurs. As the process proceeds, the polyolefin wax in the molten state thickens and the stirring efficiency decreases, and the contact efficiency between the polyolefin wax and oxygen or an oxygen-containing gas decreases. The inventor has discovered something.

SUMMARY OF THE INVENTION The present invention relates to the fact that the present inventors have found out that a relatively high molecular weight polyolefin wax is brought into contact with oxygen or an oxygen-containing gas in a molten state with stirring to convert the polyolefin wax into an acid. When a group is added, a means for suppressing the thickening of the polyolefin in a molten state is employed, and by increasing the stirring efficiency, it is possible to increase the acid group addition rate. It is an object of the present invention to provide a method for producing a polyolefin wax.

SUMMARY OF THE INVENTION The method for producing an acid group-containing polyolefin wax according to the present invention has an intrinsic viscosity [η] of 0.3 to 1.
0 dl / g of polyolefin wax (A) 100 parts by weight, and intrinsic viscosity [η] measured in decalin at 135 ° C. is 0.15 dl / g.
g of polyolefin wax (B) of 3 g or less, and the mixture is brought into contact with oxygen or an oxygen-containing gas in a molten state with stirring to obtain an acid value of 6 to 30 mgKOH / g. It is characterized by producing an acid group-containing polyolefin wax having a hardness of 0.2 mm or less.

That is, in the method for producing an acid group-containing polyolefin wax according to the present invention, a mixture obtained by mixing a relatively high molecular weight polyolefin wax (A) and a low molecular weight polyolefin wax (B) at a specific ratio is treated under a predetermined condition. And producing a relatively high molecular weight acid-containing polyolefin wax.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, a method for producing an acid group-containing polyolefin wax according to the present invention will be specifically described.

The polyolefin wax (A) used as a main raw material in the present invention has an intrinsic viscosity [η] of 0.3 to 1.0 dl / g, preferably 0.4 to 0.8 dl / g, measured at 135 ° C. in decalin. Specifically, polyethylene, polypropylene, polybutene, poly-4-methylpentene-1 and the like can be mentioned. In the present invention, polyethylene and polypropylene are preferably used.

The polyolefin wax (B) used as an auxiliary material in the present invention has an intrinsic viscosity [η] of 0.15 dl / g or less, preferably 0.05 to 0.15 dl / g, more preferably 0.06 to 0.1 dl, measured at 135 ° C. in decalin. / g, and as the polyolefin, specifically, polyethylene, polypropylene,
Polybutene, poly-4-methylpentene-1 and the like. In the present invention, polyethylene is preferably used.

In the present invention, the polyolefin wax (B) having an intrinsic viscosity [η] of 0.15 dl / g or less has a function of improving the stirring efficiency by suppressing the thickening of the main raw material polyolefin wax (A) in a molten state as a lubricant. Therefore, there is an effect that the contact efficiency between the main raw material polyolefin wax (A) and oxygen or an oxygen-containing gas is improved to increase the acid group addition rate.

In the present invention, the polyolefin wax (B) is used in an amount of 3 to 15 parts by weight based on 100 parts by weight of the polyolefin wax (A).
It is used in an amount of 5 parts by weight, preferably 5 to 10 parts by weight.

In the present invention, after the polyolefin wax (A) and the polyolefin wax (B) are mixed at the above-mentioned mixing ratio, the mixture is brought into contact with oxygen or an oxygen-containing gas in a molten state with stirring.

The mixture is usually 130 to 200 ° C., preferably 140 to 170
Melt at a temperature of ° C.

In the present invention, the oxidation reaction is carried out by bringing the mixture into contact with oxygen or an oxygen-containing gas in a molten state with stirring, and the term “oxygen or oxygen-containing gas” in the present specification refers to pure oxygen (normal liquid air). It may contain other components that are obtained by fractionation or electrolysis of water and contain oxygen as impurities), a mixed gas of pure oxygen and another gas, for example, air,
And ozone.

As a method for contacting the raw material mixture with oxygen or the like, specifically, a method in which an oxygen-containing gas is continuously supplied from the lower part of the reactor and brought into contact with the raw material mixture is preferable. In this case, it is preferable that the oxygen-containing gas is supplied so as to have an oxygen amount equivalent to 1.0 to 8.0 Nl per minute per 1 kg of the raw material mixture.

The oxidation reaction between the above-mentioned mixture and oxygen or an oxygen-containing gas is carried out in consideration of the use of the obtained acid-containing polyolefin wax and its use state, and the acid value of the acid-containing polyolefin wax as a reaction product (JIS K 5902). ) Is usually terminated when 6-30 mgKOH / g is reached. That is, in the present invention, the acid value of the obtained acid group-containing polyolefin wax is tracked, and when the acid value reaches a target acid value according to the application, the supply of oxygen or an oxygen-containing gas is stopped to terminate the oxidation reaction. .

Here, the acid value refers to the number of mg of potassium hydroxide required for neutralization per 1 g of a sample.

When the acid value of the acid-containing polyolefin wax obtained according to the present invention is 6 to 30 mgKOH / g, the intrinsic viscosity [η] of the acid-containing polyolefin wax measured in decalin at 135 ° C. is usually 0.23 to 0.45 dl. / g range,
The penetration hardness (JIS K 2207) is usually 0.2 mm or less. The acid group-containing polyolefin wax having such properties can be suitably used for applications such as fiber treatment agents, floor polish, paper treatment agents, aqueous inks, and aqueous paints.

According to the present invention, the stirring efficiency can be improved by suppressing the thickening of the relatively high-molecular-weight polyolefin wax in the molten state, so that the oxidation reaction can be performed without reducing the acid group addition rate. As a result, a relatively high molecular weight acid-containing polyolefin wax having an acid value of 6 to 30 mgKOH / g and a penetration hardness of 0.2 mm or less can be easily produced.

Hereinafter, the present invention will be described with reference to examples, the present invention,
It is not limited to these examples.

Example 1 Intrinsic viscosity [η] measured in decalin at 135 ° C. is 0.5 dl / g
After mixing 800 g of polyethylene and 80 g of polyethylene having an intrinsic viscosity [η] of 0.075 dl / g measured in decalin at 135 ° C., the mixture was stirred in a reactor equipped with a stirrer at a temperature of 160 ° C. Pure oxygen (commercial oxygen) was continuously supplied from the lower part of the reactor at a rate of 6 Nl per minute for 5 hours to obtain 875 g of an acid group-containing polyethylene wax having an acid value of 10 mgKOH / g.

The resulting acid group-containing polyethylene wax has an intrinsic viscosity [η] of 0.32 dl / g measured in decalin at 135 ° C.,
The penetration hardness (JIS K 2207) was 0.1 mm or less.

Example 2 In Example 1, a pressure of 8 kg / cm was used instead of pure oxygen.
^{In the same} manner as in Example 1 except that the mixture of Example 1 and air were contacted with pressurized air of ² (gauge pressure) for 6 hours, an acid group-containing polyethylene wax 87 having an acid value of 9.5 mgKOH / g was used.
0 g was obtained.

The resulting acid group-containing polyethylene wax has an intrinsic viscosity [η] of 0.35 dl / g measured in decalin at 135 ° C.,
The penetration hardness (JIS K 2207) was 0.1 mm or less.

Example 3 In Example 1, an intrinsic viscosity [η] of 0.06 d was used instead of 80 g of a polyethylene wax having an intrinsic viscosity [η] of 0.075 dl / g.
830 g of an acid group-containing polyethylene wax having an acid value of 10 mgKOH / g was obtained in the same manner as in Example 1 except that 40 g of 1 / g polyethylene wax was used.

The resulting acid group-containing polyethylene wax has an intrinsic viscosity [η] of 0.31 dl / g measured in decalin at 135 ° C.,
The penetration hardness (JIS K 2207) was 0.1 mm or less.

Example 4 The intrinsic viscosity [η] measured in decalin at 135 ° C. is 0.17 dl /
g of polypropylene wax and 40 g of a polyethylene wax having an intrinsic viscosity [η] of 0.075 dl / g measured in decalin at 135 ° C., and the mixture is stirred at a temperature of 170 ° C. in a reactor equipped with a stirrer. With a method of continuously supplying pure oxygen (commercial oxygen) from the lower part of the reactor at a rate of 6 Nl per minute with stirring, the mixture is contacted for 4 hours, and the acid value is 10.5 mg KO.
830 g of an H / g acid group-containing polypropylene wax were obtained.

The obtained acid group-containing polypropylene wax has a temperature of 135 ° C.
The intrinsic viscosity [η] measured in decalin was 0.1 dl / g, and the penetration hardness (JIS K 2207) was 0.1 mm or less.

Comparative Example 1 The intrinsic viscosity [η] measured in decalin at 135 ° C. was 0.5 dl / g.
100 kg of polyethylene wax in a reactor equipped with a stirrer,
While stirring at a temperature of 60 ° C., the polyethylene wax was brought into contact with air with pressurized air at a pressure of 8 kg / cm ² (gauge pressure) for 6 hours to obtain 98 kg of an acid group-containing polyethylene wax having an acid value of 4.5 mgKOH / g. .

The intrinsic viscosity [η] of the obtained acid group-containing polyethylene wax measured in decalin at 135 ° C. was 0.6 dl / g.

As shown in Table 1, the acid group-containing polyolefin wax obtained in Examples 1 to 4 has a higher acid value and an intrinsic viscosity [η] than the acid group-containing polyolefin wax obtained in Comparative Example 1. ], The thickening of the main raw material polyolefin wax during the oxidation reactions of Examples 1 to 4 is remarkably suppressed. Also, when comparing the contact time of gas and the acid value of the acid group-containing polyolefin wax of Examples 1 to 4 and Comparative Example 1, Comparative Example 1
It is understood that the acid group addition rate in Examples 1 to 4 is faster than that in Examples 1 to 4.

Continuation of the front page (56) References JP-A-51-41790 (JP, A) JP-B-43-16287 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 8 / 06 C08F 8/50

Claims (2)

(57) [Claims] 1. 100 parts by weight of a polyolefin wax (A) having an intrinsic viscosity [η] of 0.3 to 1.0 dl / g measured in decalin at 135 ° C. and an intrinsic viscosity [η] of 0.15 measured in decalin at 135 ° C. dl / g
After mixing 3 to 15 parts by weight of the following polyolefin wax (B), the mixture is brought into contact with oxygen or an oxygen-containing gas in a molten state with stirring to have an acid value of 6 to 30 mgKOH / g and a penetration hardness. For producing an acid group-containing polyolefin wax having a particle size of 0.2 mm or less. 2. The method for producing an acid group-containing polyolefin wax according to claim 1, wherein said mixture is in a molten state at a temperature of 140 to 170 ° C.